The Republican Party establishment is caught in an existential paradox.

Without Donald Trump’s populist and nationalist 2016 campaign, the GOP likely would not have won the presidency. Nor would Republicans now enjoy such lopsided control of state legislatures and governorships, as well as majorities in the House and Senate, and likely control of the Supreme Court for a generation.

So are conservatives angry at or indebted to the apostate Trump for helping them politically in a way they previously could not help themselves?

For a similar sense of the paradox, imagine if a novice outsider such as billionaire entrepreneur Mark Cuban had captured the Democratic nomination and then won the presidency — but did not run on either Bernie Sanders’ progressive redistributionism, Barack Obama’s identity politics or Hillary Clinton’s high taxes and increased regulation. Would liberals be happy, conflicted or seething?

For now, most Republicans are overlooking Trump’s bothersome character excesses — without conceding that his impulsiveness and bluntness may well have contributed to his success after Republican sobriety and traditionalism failed.

Republicans concentrate on what they like in the Trump agenda — military spending increases, energy expansion, deterrence abroad, tax and regulatory reform, and the repeal/replacement of the Affordable Care Act — and ignore the inherent contradictions between Trumpism and their own political creed.

But there are many fault lines that will loom large in the next few years.

Trump is not willing to accept a permanent Midwest Rust Belt as the price of globalization. If there are to be sacrificial lambs in world trade, for Trump it is better that they reside in China, South Korea and Germany, nations that for a change can try finding any upside to running huge trade deficits.

The Republican establishment’s employer argument is that illegal immigration ensures that the sort of work “Americans won’t do” is actually done. Or, some establishment Republicans believe that undocumented migrants who cross the southern border will one day become conservative, “family values” voters.

Not so Trumpism. It seeks to help the working class by stopping the importation of cheap labor. It believes that secure borders will restore the sanctity of law, and that the end of illegal immigration will lead to greater integration and assimilation of Latino minority groups.

In the long run, Mexico will be a better neighbor by not counting on impoverished expatriates to prop up an often corrupt government in Mexico City and by addressing the plight of its impoverished rather than exporting its poor.

Trumpism views the world abroad largely in terms of realist deterrence.

Outside the West, the world is a mess, and it will likely not change — and cannot be forced to change — because of American blood and treasure spent on trying to replicate America abroad. Instead, Trumpism seems to want to deter rivals to ensure a calm global order.

Trumpism has no illusions that there will ever be a world of liberal democracies. It seeks instead only to make sure enemies understand that any future aggression will not be worth the anticipated benefits. As for dictators such as those in the Philippines or Egypt, Trumpism argues that it makes little sense to snub autocratic friends while cutting deals with autocratic enemies like those in Iran or Cuba.

On matters of identity politics, Republicans have often sought to play down but not actively oppose racial, ethnic and gender pressure groups. The strategy has been to not antagonize the ethnic and race industries in hopes of receiving a greater share of the minority vote.

Trump is politically incorrect. He sees a person’s pocketbook, not his outward appearance, as the key to his allegiance. Through deregulation, tax reform, immigration reform and fair trade, Trump hopes to grow the economy by 3 percent each year.

Such economic growth has not happened in over a decade. But if Trumpism works, then prosperity will supposedly unite Americans to a greater degree than identity politics can divide them.

In other words, Trump apparently believes that if he achieves 3 percent GDP growth and avoids a major war abroad, his brand of economic nationalism, realist deterrence and America-first chauvinism will replace mainstream Republicanism.

If he stalls the economy or gets into a quagmire abroad, then Trump will end up like most other American populist mavericks — as an interesting footnote.